Making limed blood products for use in alkaline blood glues of normal working viscosity at high water ratios



Feb. 18, 1969 c. N. CONE ETAL 3,428,467

MAKING LIMED BLOOD PRODUCTS FOR USE IN ALKALINE BLOOD GLUES OF NORMAL WORKING VISCOSITY AT HIGH WATER RATIOS Filed Feb. 13, 1967 Cu(OH) (PERCENT) CHARLES N. CONE DALE J. HOHBACH HAROLD A. SMITH INVENTORS BY ATTY.

United States Patent 6 Claims ABSTRACT OF THE DISCLOSURE A blood product useful in the manufacture of alkaline blood glues of normal working viscosity at high water ratios is manufactured by reacting declotted animal blood with lime. The resulting product then may be spray dried to make a powdered blood glue base convertible into a glue by mixing it with water and selected glue making chemicals.

This invention relates to a process of making a blood product for use in the manufacture of alkaline blood glues.

Blood glues conventionally are made by collecting animal blood from the slaughterhouse floor, declotting the blood, and spray drying it to form a soluble blood glue base. The glue base is transported to the glue manufacturing plant where it is formulated into the finished glue by mixing it with water and such glue-base-dispersing chemicals as sodium silicate, caustic soda, lime and an anti-foaming agent. Soya meal, other proteins, and fillers also may be included in the formulation.

The viscosity of the resulting glue is determined largely by the nature of the blood glue base and itself determines the amount of water which may be included in the glue mix. In general, where a particular glue base has high viscosity-imparting properties, a correspondingly large amount of water may be employed without sacrifice of glue spreadability, adhesive qualities and other desirable properties. Accordingly, blood products Which uniformly impart to blood glues in which they are incorporated a working viscosity and good stability at high water ratios are highly desired by the glue maker. Further desired are blood glue bases which, no matter what their source or prior history, may be used in the formulation'of glues of uniform and reproducible properties.

It is the general object of the present invention to provide a process for converting animal blood into a blood glue base which is useful in the production of blood glues of normal and consistently uniform working viscosity and uniform properties, which is stable over a long period of time, and which greatly extends the water capacity of the glue without impairing its adhesive qualities.

It now has been discovered, and it is the essence of the present invention, that a blood product having the ability to impart unusually high water ratios, While maintaining normal working, and stable, viscosity characteristics, to blood glues in which it is incorporated may be produced by reacting declotted animal blood with from 01-25% by weight hydrated lime, blood solids basis, at a temperature between the freezing temperature of water and the coagulation temperature of the blood "ice mixture. The blood thereafter may be spray dried or otherwise converted to a glue-making blood base of uniformly high and stable viscosity-imparting properties.

The single figure of the drawing is a graph illustrating the relationship between the amount of hydrated lime reacted with the blood and the viscosity of the glues made from the resulting limed blood base.

In carrying out the process of the invention, animal blood is collected and processed promptly after it has been obtained, or in any event, before the natural degradation processes have proceeded to a substantial degree.

In the first step of the procedure the blood is declotted to facilitate its subsequent reaction with the lime as well as to facilitate the spray drying operation by which it preferably is dehydrated.

Preferably before it has lost its native heat, the declotted liquid blood is introduced into a suitable reaction vessel equipped with means for agitation. There it is treated at once with either slaked or unslaked lime. Where unslaked lime is used, it is converted to slaked lime promptly upon its introduction into the reaction mixture. Preferably, however, the solid lime, either slaked or unslaked, is mixed with Water, used in the proportion of about one part of lime and about two parts of water, to form a hydrated lime slurry. This slurry then is introduced into the declotted blood slowly and with continual stirring.

The amount of lime thus added is somewhat variable depending upon such factors as the nature of the blood and the type of glue subsequently to be manufactured. In general, a sufficient amount of lime should be employed to affect the viscosity appreciably. On the other hand, if too much lime is used, it causes an undesirable gelling effect. Accordingly from 0.1% to 25%, preferably from 0.l10% by weight, dry blood solids basis, of hydrated lime is used.

The temperature within the reaction vessel should be maintained at a level which is above the freezing temperature of the mixture, but below its coagulating temperature, i.e. from 32-120" F. Slaughterhouse blood normally has a temperature of from l00 F. Blood at this temperature may be employed to advantage in the instant process, without further temperature adjustment.

The treatment with lime in the indicated amount at the indicated temperature is carried out with agitation until the reaction which occurs has been completed. The reaction time is determined to some extent by the temperature and concentration of the reaction mixture. In general, however, a reaction time of from 10 minutes to 3 hours sufiices, the time being in inverse ratio to the temperature.

After the reaction is complete, the reaction mixture need not be dehydrated immediately. In accordance with established plant schedules, it may be processed for the removal of water and conversion to a solid blood product.

Water removal may be accomplished by any of the usual techniques which do not affect the blood adversely. Thus it may be dried on a heated vacuum drum. Preferably, however it is spray dried by atomizing it and mixing it with hot air at a temperature which is sufficient to dry the blood rapidly while still leaving it dispersable in alkaline glue-making mixtures. This may be accomplished by mixing it with air at a temperature of from 300500 F. at the time of introducing the liquid blood into the drier, and retaining it in the drier for a time period of from 2-20 seconds. The dried, limed blood then may be sacked and stored under usual atmospheric conditions for any desired length of time Without danger of loss to its glue making properties.

After having passed through the channels of commerce, the limed blood may be formulated into alkaline blood glue by the glue manufacturer or the plywood manufacturer who mixes it with the usual glue-making chemicals. These may include protein-dispersing agents such as sodium silicate, caustic soda and lime; pine oil and other anti-foaming agents; fillers such as wood flour, bark powder and walnut shell flour, and proteins other than blood such as soya flour, cottonseed meal, peanut meal, fish meal and casein, all used in proportions calculated to produce a glue of desired properties.

It is to be noted in this connection that the lime employed at this stage serves a different function that the lime employed in the original reaction between the declotted blood and the lime. The lime added in the glue loft does not exert the above noted significant effect on glue viscosity. It is added primarily for its conditioning effect in giving a grainy texture to the glue mix and improving its spreadability.

Typical glue formulations incorporating the herein described lime-reacted blood product, which formulations may be mixed and applied in the usual manner, are given in Tables I and II below.

TABLE I Parts by weight (dry solids basis) Glue-making protein consisting of 100% by weight of lime-reacted animal blood, and 0-95 by Weight of other glue-making pro- The presently described process for making a lime-reacted glue base is indicated in the following examples, wherein parts are given in parts by weight.

Example 1 This example illustrates the effect of using various amounts of lime on the viscosity-imparting qualities of a blood glue base with which the lime is reacted.

1 pound of powdered lime is mixed with 2 pounds of Water to form a slurry. The slurry is added slowly, with stirring, to declotted, liquid animal blood, contained in a reaction vessel provided with means for agitation.

The blood was obtained fresh from the slaughterhouse and had its inherent temperature of about 95 E, which temperature was maintained during the reaction without the application of additional heat, possibly because of the mildly exothermic character of the reaction with lime.

After a reaction period of one-half hour, the limereacted blood was spray dried by atomizing it in hot air at a temperature of from 300-500 F. and spraying it into a drier, where itv is held at the indicated temperature for a time period of from 220 seconds.

TABLE III Lime, percent Viscosity (poises) by weight (Dry Solids 5' 30 60' Basis) The results given above with respect to the five minute viscosity values are plotted in the single figure of the drawings. Inspection of this figure indicates the very material improvement in glue viscosity achieved by reacting the declotted blood with lime. It also illustrates the critical character of the amount of lime used, a maximum effect being obtained at a lime usage of between 8 and 12% by weight. L

This example was repeated using, in place of the lime, magnesium hydroxide, magnesium oxide, strontium hydroxide, strontium oxide, barium oxide, chromic oxide, cobalt oxide, and aluminum hydroxide. None of these materials, although in certain respects showing qualities similar to that of lime, demonstrated the remarkable property exhibited by lime of greatly enhancing the viscosity-promoting properties of a lime-treated blood glue base.

Example 2 This example illustrates the plant scale application of the invention.

The procedure of Example 1 was followed using various percentages of lime to react with the blood in the manufacture of the blood glue base. The glue base then was made up into glues, again using the procedure of Example 1 and the viscosities taken at 5', 30' and 60' intervals. The results are given in Table IV.

TABLE IV Lime, percent Viscosity (polses) by weight (Dry Solids 5 30 60 Basis) It is apparent from the foregoing that the glues manufactured from the blood glue base provided by the process of the invention have stable viscosities over the usual plywood mill operating schedules.

Example 3 TABLE V Lime, percent by Age of Blood Viscosity (poises) weight (Dry Solids Glue Base,

Basis) months 60 Days From the foregoing results it will be seen that the lime treated blood glue base powders of the invention posses a high degree of aging stability and thus are suitable for ordinary commercial use.

Having thus described our invention in preferred embodiments, what is claimed as new and desired to protect by Letters Patent is:

1. The process of making a lime-treated blood base for use in the manufacture of alkaline blood glues of normal working viscosity at high Water ratios, which comprises:

(a) declotting animal blood, and

(b) reacting the declotted uncoagulated liquid blood with from 01-25% by weight based on the Weight of blood solids, of hydrated lime,

(c) the reaction being carried out at a temperature of from 32 to 120 F.

2. The processof claim 1 wherein the liquid blood is reacted with from 01-10% by weight of hydrated lime, dry blood solids basis.

3. The process of claim 1 wherein the reaction between the lime and the liquid blood is carried out for a reaction time period of from 10 minutes to 3 hours.

4. The process of claim 1 including the step of spraydrying the reaction mixture to form a solid, lime-treated, blood glue base.

6 5. A lime-treated blood glue comprising Parts by weight (dry solids basis) Glue making protein comprising 5l00% by weight of uncoagulated, liquid animal blood which has been reacted at a temperature of from 32-120 F. with from 01-25% by Weight, dry solids basis, of calcium hydroxide;

and 095% of other glue-making protein 100 Dispersing agent for dispersing glue-making proteins in aqueous medium and comprising at least one member of the group consisting of sodium silicate, caustic soda, and lime l-250 Alkaline blood glue filler 0-150 Water -1200 6. A lime-treated glue comprising Parts by weight (dry solids basis) Glue making protein comprising 5l00% by Weight of lime-reacted liquid, uncoagulated animal blood and 0-95% by weight of other glue-making protein Caustic soda 515 Sodium silicate 10-100 Lime 535 Alkaline-'blood-glue filler 10-100 Water 60-1200 References Cited UNITED STATES PATENTS 2,895,928 7/1959 Cone 260-7 3,080,244 3/1963 Cone et a1 106-124 JULIUS FROME, Primary Examiner.

T. MORRIS, Assistant Examiner.

US. Cl X.R. 260-112 

